The Westbrook that played with KD isn't the same player that he has been over the last few years. For the most part, he'd actually play defense back then, and wasn't exerting all his energy hunting for box score stats. His aggression and ability to keep dictate possessions played an integral part in OKC going on deep playoffs runs.
What happened to KD in the 2013 postseason when Westbrook got injured in the first round? He ended up falling to the Grizzles 1-4 in the next round.
He was going up against the best defense in the league with the DPOY (Marc) and best perimeter defender (Tony) while his teammates was Kevin Martin (out of the league 2 seasons later), rookie Reggie Jackson, 38yo Derek Fisher (out the league next season), Serge Ibaka, Thabo Sefolosha, Nick Collison, Hashem Thabeet (out the league next season) and Kendrick Perkins(worst player in the league).
Perkins had the worst series in NBA history. Negative PER. Nick Collison was horrible too. Couldnt rebound and was turning it over like a factory. Even on defense ZBo and Marc was cooking them.
Thabo shot 20% from 3 and thats all he could do on offense. Rookie Reggie was their 2nd best player. No player in NBA history beating that Grizz defense with that roster.
Look at game 2 KD had 36/11/9 on 52/33/92 and they still lost b/c their roster. But they lost b/c...
Ibaka 11/5/0 5 PF 5-12 FG 1-2 3P 0-0 FT
Perkins 4/3/3 2 TOV 4 PF 1-4 FG 2-3 FT
KMart 6/1/1 1 TOV 2-11 FG 0-2 3P 2-2 FT
Reggie 10/5/2 3 TOV 3-8 FGA 0-3 3PA 4-4 FTA
Thabo 7/3/3 2 TOV 2-4 FGA 1-3 3PA 2-2 FTA
Collision 0/0/0 4 TOV 6 PF
Thabeet 0/3/0 2 PF
Combined: 38 points 20 rebs 9 assists 12 TOV 21 PF on 13-40 FGA 2-10 3PA in 183 combined minutes
A center managed to have 0 rebounds in 15 minutes

. He fouled out in that short span of time. Oh and he somehow had 4 TOVs despite attempting 0 shots, 0 rebounds, and only creating 1 assist. Excluding KD, OKC's entire front court rotation got murdered.
Mike Conley and Marc Gasol combined for 50/15/14 4 TOV on 19-35 FGA 2-7 3PA and 10-11 FTA. They literally outplayed KD's entire front court rotation and starting backcourt by themselves.
For that Memphis series while getting 23.3 MPG Kendrick Perkins managed
-2.4 ppg 4.2 rpg 0.8 ast with 2.0 TOV and .6 BLK on 23.3 TS%
-Almost as many turnovers(10) as total points(12)
-Almost as many Fouls(18) as Total Rebounds(21)
-More Bad Pass turnovers(7) than Assists(4)
-His shot was blocked(11) almost 4 times as much as he blocked another shot(3)
-He shot 16.7%(4-24) from the field including 1-9(11.1%) on layups and 1-13 on jumpshots(7.7%)
-His Offensive Rating(44) is the lowest ever in a series for a player averaging >20 minutes
-His Net Rating was was -56
-His Game Score for the series was NEGATIVE(-0.6). That means, statistically, he was actually detrimental to his team
-His TOV%(28.0) was 5 times higher than his AST%(5.3)
-He allowed Marc & ZBo to combine for 37.8/19.2/4.6 with only 15 total turnovers in 5 games
-Memphis SG Tony Allen had a TRB% equal to Perkins for the series(10.3%)
Perkins also became the 1st player in NBA history to post a negative PER for the playoffs (-6.7). That means his team would have been better off on offense had he just stayed at the opposite end of the court while OKC had the ball. Additionally, OKC despite losing in 5 games was actually + every game with Perkins off the court. +10 G1, +4 G2, 0 G3, 0 G4, +6 G5
And for OKC's backup C? Perkins TOV%(28.6%) would have been the the highest ever for a 5 game series, but his backup Nick Collison actually blew that number out of the water with his own 34.8%. Collison managed 10 turnovers in 88 total minutes. He actually did accumulate more fouls(26) than total rebounds(20) or total points(18).
No one saying Russ was a bad player he just very flawed specially for a 1st or 2nd option. And it shows more in the playoffs like we seen him in in the playoffs the rest of his career after KD dipped.